Hissing females of great tits (Parus major) have lower breeding success than non-hissing individuals

Antipredator strategies vary remarkably between individuals within populations. Parents tend to take greater risks when brood value is increased. Moreover, individuals consistently differ in a whole suite of correlated behaviours that may cause distinctive responses to predators. It is likely that individual differences in antipredator behaviour may co-vary with proxies for fitness such as reproductive success. We used a 4-year data from wild great tits (Parus major) to test whether passive and active antipredator strategies (females with no response vs. those giving hissing calls towards a nest predator) during the incubation stage can reflect variation in breeding success. Although clutch size did not depend on hissing behaviour, the number of surviving offspring from eggs and neonates to fledglings was higher for non-hissing than hissing birds. We conclude that females with distinct antipredator strategies can prioritize different fitness components.